Paul F. Sydney

The Near-Earth Asteroid Tracking (NEAT) Program: An Automated System for Telescope Control, Wide-Field Imaging, and Object Detection

The Near-Earth Asteroid Tracking (NEAT) system operates autonomously at the Maui Space Surveillance Site on the summit of the extinct Haleakala Volcano Crater, Hawaii. The program began in 1995 December and continues with an observing run every month. Its astrometric observations result in discoveries of near-Earth objects (NEOs), both asteroids (NEAs) and comets, and other unusual minor planets. Each six-night run NEAT covers about 10% of the accessible sky, detects thousands of asteroids, and detects two to five NEAs. NEAT has also contributed more than 1500 preliminary designations of minor planets and 26,000 detections of main-belt asteroids. This paper presents a description of the NEAT system and discusses its capabilities, including sky coverage, limiting magnitude, and detection efficiency. NEAT is an effective discoverer of NEAs larger than 1 km and is a major contributor to NASAs goal of identifying all NEAs of this size. An expansion of NEAT into a network of three similar systems would be capable of discovering 90% of the 1 km and larger NEAs within the next 10–40 yr, while serving the additional role of satellite detection and tracking for the US Air Force. Daily updates of NEAT results during operational periods can be found at JPLs Web site (http://huey.jpl.nasa.gov/~spravdo/neat.html). The images and information about the detected objects, including times of observation, positions, and magnitudes are made available via NASAs SkyMorph program.

Spectroscopic observations of space objects and phenomena using Spica and Kala at AMOS

The Spica and Kala spectrographs located at the rear blanchard of the 1.6 m telescope and the trunnion port of the AEOS 3.67 m telescope, respectively, have been utilized by several DoD and NASA agencies requiring relatively high resolution spectroscopic observations. The sensors are located at the Air Force Maui Optical Station (AMOS), Haleakala, Maui. Three R&D programs utilizing these instruments will be described. The AFRL propulsion directorates demonstration called the electric propulsion space experiment (ESEX) utilized Spica to evaluate high powered arc-jet thruster firings from the ARGOS satellite. AFRL Det. 15 and Air Force Battlelab sponsored a project called SILC to explore the advantages of applying spectroscopic analysis to help reduce satellite cross- tagging and augment Satellite Object Identification (SOI). Thirdly, the NASA Johnson Space Center Space Debris Program obtained spectroscopic data on Low Earth Orbit (LEO) targets to help determine albedo and material composition of space debris.

Raven automated small telescope systems

The Raven optical sensor is a commercial system being developed and tested by the Air Force Research Laboratory. It allows for a low cost method for obtaining high accuracy angular observations of space objects (manmade and celestial) with a standard deviation of approximately one arcsecond or less. Presented here is an overview of the past and present successes and future projects utilizing Raven. This system has evolved into a very viable and cost effective solution for obtaining low-cost observations for satellite and asteroid catalog and follow-up maintenance. Collaborative efforts between AFRL and several space agencies (JPL, NASA, Space Battlelab, Canadian Defense Ministry, etc) have successfully demonstrated and utilized the Raven system for their missions, including improved satellite orbit determination accuracy, NEO follow-ups, and remote autonomous collecting and reporting of metric data on deep space objects.

Phoenix Telescope at AMOS: return of the Baker-Nunn camera

The number of objects orbiting the Earth has been increasing dramatically since the launch of Sputnik in the late 1950s. Thousands of orbiting objects, active satellites or debris, need to be tracked to ensure the accuracy of their orbital elements. To meet the growing needs for space surveillance and orbital debris tracking, the Air Force Maui Optical and Supercomputing Site (AMOS) on Maui, Hawaii is bringing back one of the original Baker-Nunn cameras as the Phoenix Telescope to contribute to these efforts. The Phoenix Telescope retains the wide-field attribute of the original system, while the addition of enhanced optics allows the use of a 4k × 4k pixels back-illuminated CCD array as the imaging camera to provide a field-of-view of 6.8 degrees square (9.6 degrees diagonal). An integrated software suite automates the majority of the operational functions, and allows the system to process in-frame multiple-object acquisitions. The wide-field capability of the Phoenix Telescope is not only an effective tool in the space surveillance effort, but it also has a very high potential value for efforts in searching for and tracking Near-Earth objects (NEO). The large sky coverage provided by the Phoenix Telescope also has the potential to be used in searching for supernova and other astronomical phenomena. An overview of the Phoenix system and results obtained since first-light are presented.

Deep space satellite observations using the near-Earth asteroid tracking (NEAT) camera at AMOS

The AMOS 1.2-m telescope is being used 18 nights per month to search for Near-Earth Asteroids (NEA). Since telescope time is a very valuable resource, our goal is to use the telescope as efficiently as possible. This includes striving to maximize the utility of each observation. Since the NEAT searches are within the ecliptic, the same part of the sky as geosynchronous satellites, these search fields contain satellite tracks as well as asteroids. We present the results of simulations of the number of satellites that should be found within the field of view based upon the field centers and times for several nights. We have also examined the NEAT images for geosynchronous objects and present these results. During the remaining nights each month, we use the NEAT camera to obtain observations of deep-space satellites. This data will also be presented. We also present the results of simulations for optimizing search strategies for deep-space objects using NEAT and other AMOS sensors.

Determining the material type of man-made orbiting objects using low-resolution reflectance spectroscopy

The purpose of this research is to improve the knowledge of the physical properties of orbital debris, specifically the material type. Combining the use of the fast-tracking United States Air Force Research Laboratory (AFRL) telescopes with a common astronomical technique, spectroscopy, and NASA resources was a natural step toward determining the material type of orbiting objects remotely. Currently operating at the AFRL Maui Optical Site (AMOS) is a 1.6-meter telescope designed to track fast moving objects like those found in lower Earth orbit (LEO). Using the spectral range of 0.4 - 0.9 microns (4000 - 9000 angstroms), researchers can separate materials into classification ranges. Within the above range, aluminum, paints, plastics, and other metals have different absorption features as well as slopes in their respective spectra. The spectrograph used on this telescope yields a three-angstrom resolution; large enough to see smaller features mentioned and thus determine the material type of the object. The results of the NASA AMOS Spectral Study (NASS) are presented herein.

New home for NEAT on the 1.2m/B37 at AMOS

The NASA/JPL Near Earth Asteroid Tracking (NEAT) Program was in operation using the Maui GEODSS as its observing platform for about three years starting in late 1995 and continuing into 1998. In October of 1998 the NASA/AFSPC Near Earth Object Working Group (NEOWG) recommended that the NASA/JPL NEAT program be moved to the AMOS 1.2 m/B37 telescope. This paper describes the technical efforts that were required to facilitate the move. The task requirements specified that the modified 1.2 m/B37 system be capable of producing a field of view (FOV) greater than or equal to 1.4 degrees X 1.4 degrees at the NEAT camera focal plane. Further, it was specified that no modifications be made to the 1.2 m/B37 mirror or the NASA/JPL camera. Thus, activity focused on the development of suitable focal reduction optics (FRO). A new headring and spider, based on the original design, were also built to receive the NEAT FRO and the NASA/JPL camera. Operation of the NEAT system, for asteroid search and discovery, will be autonomous and remotely directed from NASA/JPL. Finally, the potential for use of the NEAT system as regards the satellite metric mission will also be presented.

Relay Mirror Experiment scoring analysis and the effects of atmospheric turbulence

The Relay Mirror Experiment is a space experiment in which an IR laser beam is propagated from one ground station, the Laser Source Site (LSS), to an orbiting relay mirror and back to another ground station, the Target Scoring System (TSS). A sparse array of 37 telescopes senses the position of the relayed beam at the second ground station for purposes of scoring the pointing capability of the relay mirror. Data from these telescopes is processed to determine the position of the beam as a function of time. These signals contain the effects of atmospheric turbulence on both the uplink and downlink of the IR beam. Spectral and correlation analysis is used on the telescope data to minimize the effects of atmospheric turbulence, as well as other environmental effects.

Characterization of the near-Earth Asteroid 2002 NY40

Abstract : In August 2002, the near-Earth asteroid 2002 NY40, made its closest approach to the Earth. This provided an opportunity to study a near-Earth asteroid with a variety of instruments. Several of the telescopes at the Maui Space Surveillance System were trained at the asteroid and collected adaptive optics images, photometry and spectroscopy. Analysis of the imagery reveals the asteroid is triangular shaped with significant self-shadowing. The photometry reveals a 20-hour period and the spectroscopy shows that the asteroid is a Q-type.

Geosynchronous Earth orbital debris campaign

The National Aeronautics and Space Administration (NASA) Johnson Space Center (JSC) is conducting systematic searches of the Geosynchronous Earth Orbit (GEO) environment as part of an international measurement campaign under the auspices of the Inter-Agency Space Debris Coordination Committee (IADC). The objectives for this survey are to determine the extent and character of debris in GEO, buy obtaining distributions for the brightness, inclination, Right Ascension of Ascending Node (RAAN), and mean motion of the debris. The Charged Coupled Device (CCD) Debris Telescope (CDT), an automated 0.32 meter aperture, transportable Schmidt telescope presently located at Cloudcroft, New Mexico, is used nightly to monitor the GEO debris environment. The CDT is equipped with a CCD camera capable of detecting 17th magnitude objects in a 20 second exposure. This corresponds to a 0.6 meter diameter object having a 0.2 albedo at 36000 km. Two other larger telescopes have been used for this purpose, the United States Naval Observatorys new 1.3 meter telescope located in Flagstaff Arizona and a 0.6 m Schmidt telescope located at Cerro Tololo Inter-American Observatory (CTIO) near La Serena Chile. Data reduction and analysis software used to reduce this data exploit tools developed by both the astronomical and DoD communities. These tools and data results are presented.